The global economic expansion has stressed the transportation industry's ability to keep up with the shipping demands for raw materials and finished products. Indeed, the demand for qualified tractor-trailer drivers has far outstripped the ability of the industry to recruit and train individuals to fill the demand of the marketplace. As a result, the demand of the transportation industry to utilize the existing personnel and vehicles has resulted in increased time spent on the road and in the vehicles in an attempt to meet the market demands.
In an effort to maintain the safety of the highways, federal regulations governing the amount of time that a driver may spend behind the wheel have been instituted. When such maximum times have been reached, the driver is required to take his vehicle off the road and rest. The number of trucks pulled over at toll plazas, weigh stations, and rest stops illustrates the compliance with such regulations. However, these locations often do not provide a place for the drivers to rest. This necessitates continued occupancy within the vehicle.
In response to the needs of the transportation industry and in recognition of the locations where drivers are forced to rest, over-the-road vehicle manufacturers have continued to increase their emphasis on ergonomic factors in the design and manufacture of their vehicles. Indeed, the interior of a modern over-the-road vehicle contains many features to minimize the stress and fatigue placed on the drivers during the operation of the vehicle. These features include, for example, vibration dampers and lumbar supports in the seats, increased sound insulation, and heating, ventilation, and air conditioning (HVAC) systems that provide a comfortable environment for the driver. To accommodate the required rest periods, and in recognition of the increased usage of driving teams that typically include two individuals, one who drives while the other sleeps, many over-the-road vehicles include a sleeping compartment. This sleeping compartment is also temperature controlled so that any time spent therein provides the occupant with a comfortable and restful experience.
To condition the sleeping compartment, many of the air conditioning systems in over-the-road trucks employ engine-belt driven compressors. While these engine-belt compressors are well-suited to circulate and pump refrigerant through the air conditioning system while the engine in the truck is running, they are not able to operate when the engine is turned off. As a result, the air conditioning system cannot cool the sleeping compartment unless the engine of the over-the-road vehicle is left running. Unfortunately, leaving the engine running simply to provide air conditioning to the cab wastes money and increases the pollution produced over the life of the truck.
To address this problem, some of the newest over-the-road trucks are manufactured with no-idle air conditioning systems. The no-idle air conditioning systems are able to provide cooling and/or heating of the passenger compartment when the engine of the truck is turned off. Such no-idle air conditioning systems may typically use a direct current (DC) motor-driven, variable speed compressor powered by one or more batteries instead of the engine belt. By using a DC motor-driven compressor, the no-idle air conditioning system is able to cool the sleeping compartment even when the engine in the vehicle is turned off. Such a no-idle system is disclosed in U.S. Pat. No. 6,889,762, entitled Vehicle Air Conditioning And Heating System Providing Engine On And Engine Off Operation, and assigned to the assignee of the instant application, the teachings and disclosure of which are incorporated herein in their entireties by reference thereto.
Unfortunately, many newly manufactured over-the-road vehicles, and nearly all existing over-the-road vehicles do not include such a no-idle air conditioning system. As a result, truck operators are often forced to choose between two less than ideal situations while trying to comfortably rest. First, they may choose to continuously run their vehicle's engine, often all night, to provide air conditioning while they rest. This first option greatly increases the cost of operating the over-the-road vehicle and increases the pollution produced by the truck since the engine must remain running, which burns additional fuel, simply to operate the air conditioning system.
Alternatively, the truck operator may choose to turn off the engine and try to rest in a non-temperature controlled environment. If the outside temperature and/or humidity at the location where the vehicle is parked are high, getting sufficient rest is difficult. While this second option does not increase the cost of operating the vehicle since the engine is turned off, the driver may not be able to adequately rest due to the elevated and uncomfortable temperature in the sleeping compartment. Therefore, operational safety of the over-the-road vehicle is potentially reduced.
For those new and existing trucks that do not have a no-idle air conditioning system, installing or retrofitting a no-idle system in the truck can be an arduous task. This is due, in no small part, to the limited amount of space that is available. In addition, if attempts are made to force a no-idle air conditioning system into too small of an area, warm and/or hot air generated by the compressor and the condenser in the system cannot be adequately and sufficiently expelled. As a result, the efficiency of the no-idle air conditioning system is greatly reduced and cooling power mitigated.
Therefore, there exists a need in the art for a vehicle air conditioning system that can efficiently provide conditioning of the interior of the vehicle, whether or not the engine in the vehicle is running, and that can be easily and/or modularly installed in the vehicle. The invention provides such an air conditioning system. These and other advantages of the invention, as well as additional inventive features, will be apparent from the description of the invention provided herein.